package org.emergent.android.weave.client;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

class Hex {
	private static final HexEncoder encoder = new HexEncoder();

	/**
	 * decode the Hex encoded input data. It is assumed the input data is valid.
	 * 
	 * @return a byte array representing the decoded data.
	 */
	public static byte[] decode(byte[] data) {
		ByteArrayOutputStream bOut = new ByteArrayOutputStream();

		try {
			encoder.decode(data, 0, data.length, bOut);
		} catch (IOException e) {
			throw new RuntimeException("exception decoding Hex string: " + e);
		}

		return bOut.toByteArray();
	}

	/**
	 * decode the Hex encoded String data - whitespace will be ignored.
	 * 
	 * @return a byte array representing the decoded data.
	 */
	public static byte[] decode(String data) {
		ByteArrayOutputStream bOut = new ByteArrayOutputStream();

		try {
			encoder.decode(data, bOut);
		} catch (IOException e) {
			throw new RuntimeException("exception decoding Hex string: " + e);
		}

		return bOut.toByteArray();
	}

	/**
	 * decode the Hex encoded String data writing it to the given output stream,
	 * whitespace characters will be ignored.
	 * 
	 * @return the number of bytes produced.
	 */
	public static int decode(String data, OutputStream out) throws IOException {
		return encoder.decode(data, out);
	}

	/**
	 * encode the input data producing a Hex encoded byte array.
	 * 
	 * @return a byte array containing the Hex encoded data.
	 */
	public static byte[] encode(byte[] data) {
		return encode(data, 0, data.length);
	}

	/**
	 * encode the input data producing a Hex encoded byte array.
	 * 
	 * @return a byte array containing the Hex encoded data.
	 */
	public static byte[] encode(byte[] data, int off, int length) {
		ByteArrayOutputStream bOut = new ByteArrayOutputStream();

		try {
			encoder.encode(data, off, length, bOut);
		} catch (IOException e) {
			throw new RuntimeException("exception encoding Hex string: " + e);
		}

		return bOut.toByteArray();
	}

	/**
	 * Hex encode the byte data writing it to the given output stream.
	 * 
	 * @return the number of bytes produced.
	 */
	public static int encode(byte[] data, int off, int length, OutputStream out)
			throws IOException {
		return encoder.encode(data, off, length, out);
	}

	/**
	 * Hex encode the byte data writing it to the given output stream.
	 * 
	 * @return the number of bytes produced.
	 */
	public static int encode(byte[] data, OutputStream out) throws IOException {
		return encoder.encode(data, 0, data.length, out);
	}
}
